Hepatocellular carcinoma in cirrhotic livers: detection with unenhanced and iron oxide-enhanced MR imaging

PURPOSE

To evaluate diagnostic accuracy with unenhanced and superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging for detection of hepatocellular carcinoma (HCC) in cirrhotic livers.

MATERIALS AND METHODS

Fifteen patients with 26 histologically proved HCCs associated with liver cirrhosis underwent imaging with T1-, T2-, and proton-density-weighted spin-echo (SE) and fast low-angle shot (FLASH) sequences. Lesion-to-liver contrast-to-noise ratios were measured in all sequences. Diagnostic performance of the imaging techniques was assessed by using receiver operating characteristic analysis.

RESULTS

Enhanced SE and FLASH sequences were significantly more accurate (P < .005) for the detection of small HCCs. Among the unenhanced pulse sequences, the accuracy of tumor localization was highest with the T2-weighted SE sequences; however, 25% of the lesions were located incorrectly. Compared with unenhanced images, lesions were correctly located more often when SPIO-enhanced SE and FLASH sequences were used.

CONCLUSION

SPIO-enhanced MR imaging with proton-density-weighted or FLASH sequences was more accurate in the detection of small HCCs in cirrhotic livers.

Effect of cold-restraint stress on immunoreactive thyrotropin-releasing hormone and immunoreactive somatostatin in the rat stomach

The effects of cold-restraint stress on immunoreactive thyrotropin-releasing hormone (ir-TRH) and immunoreactive somatostatin (ir-SOM) concentrations in the rat stomach were investigated. Rats immobilized with a spring-loaded metallic plate were placed in a room maintained at 4 degrees C for 1-3 h and then decapitated serially for investigation. Gastric ir-TRH and ir-SOM concentrations were measured by individual radioimmunoassays. Cold-restraint stress induced gastric mucosal lesions as well as a decrease of the ir-TRH concentration in the glandular stomach, an increase of the ir-TRH concentration in the gastric juice, and a decrease in gastric pH. In contrast, this stress caused an increase of ir-SOM in the glandular stomach and a decrease of ir-SOM in the gastric juice. However, cold or restraint stress alone did not induce gastric mucosal lesions or changes in gastric ir-TRH and ir-SOM concentrations or the gastric pH. To clarify the endocrine influence of peripheral TRH, pretreatment with thyroid hormone was performed to inhibit elevation of the serum TRH level during cold-restraint stress. Despite this pretreatment, cold-restraint stress still induced ulcer formation, along with changes in gastric ir-TRH and ir-SOM concentrations and gastric pH. These findings suggest that changes in gastric ir-TRH and ir-SOM concentrations may be closely related to ulcer formation due to cold-restraint, and that TRH may act in a paracrine manner in the stomach.

Nucleotide sequence and characterization of the large mitochondrial rRNA gene of Penicillium urticae, and its comparison with those of other filamentous fungi

The nucleotide sequence of a large rRNA gene and its flanking regions in cloned fragments of mitochondrial DNA from a patulin producer, Penicillium urticae NRRL2159A, was determined by dideoxy sequencing, and the 5' end and intron-exon border of the 1-rRNA gene were determined by primer extension analysis and RNA sequencing, respectively. In addition to the extensive sequence homology of the 3' end of the P. urticae mt 1-rRNA gene with those of Aspergillus nidulans and Neurospora crassa, the P. urticae gene had a 1,685 bp intron which separates a 3,307 bp 5' exon and a 583 bp 3' exon. In spite of being closely related Penicillium species, the size of the 5' exon of the P. urticae mt 1-rRNA is 472 bp larger than that of P. chrysogenum, whereas the sizes of the 3' exon and intron of P. urticae are very similar to those of P. chrysogenum (581 bp for the 3' exon and 1,678 bp for the intron). The intron of P. urticae contains a structure similar to the consensus one of the self splicing group IA intron and a large open reading frame suggested to be a gene for ribosomal protein S5. A sequence similar to the I-SceI recognition sequence was found at the exon-intron border. Extensive sequence homology was observed between P. urticae and P. chrysogenum, exceptions being in four regions in the 5' exon. These non-homologous regions were located in the hairpin and variable regions outside of the core structures. Comparison of the mt 1-rRNA sequences of several filamentous fungi revealed that the above four non-homologous regions are greatly expanded, and two other non-homologous regions appear at the 3' ends of the 5' exon and 3' exon.

N-terminal truncated insulin-like growth factor-I in human urine

Urinary insulin-like growth factor-I (IGF-I) from healthy human subjects was examined using two antisera directed toward the whole molecule (WM) and the N-terminal of IGF-I. Pooled urine samples from normal adults were dialyzed, lyophilized, then subjected to Sephacryl S-200 chromatography. The gel filtration profile of immunoreactive IGF-I measured by RIA using WM antiserum showed two peaks. Of the total IGF-I, approximately 40% was free, and the rest was present as a 50-kilodalton complex. To characterize the IGF-I forms present in those two peaks, antibody capture enzyme-linked immunoassays (EIA) using the two antisera were established for detection of intact IGF-I and N-terminal-truncated IGF-I variants. The WM antibody recognizes intact IGF-I and des(1-3)-IGF-I, an N-terminal-truncated variant, equally well, whereas the N-terminal IGF-I antibody recognizes intact IGF-I, but not des(1-3)-IGF-I (< 1% cross-reactivity). As both antibodies show similar cross-reactions with IGF-II, the difference between IGF-I levels recognized by the two antisera was considered to indicate the presence of N-terminal-truncated IGF-I variants. Of the free immunoreactive IGF-I in the urine, 64% was not recognized by N-terminal IGF-I antiserum and was considered to represent N-terminal-truncated IGF-I. In contrast, only 6% of the IGF-I present in the 50-kilodalton fraction was truncated. Urine samples from normal human subjects were analyzed by RIA with WM antiserum and EIA with both WM and N-terminal IGF-I antisera after extraction of IGF-I from binding proteins. IGF-I values measured by EIA with the WM antiserum correlated well with those values obtained by RIA using WM antiserum (r = 0.98; P < 0.001). The total urinary IGF-I level measured by EIA with the WM antiserum was 216.0 +/- 41.1 ng/L (mean +/- SEM), and 35.2 +/- 6.1% of this was considered to represent N-terminal-truncated IGF-I. Using an immobilized biotinylated peptide corresponding to the N-terminal six amino acids of IGF-I, we detected proteolytic activity toward the N-terminal of IGF-I in all four human serum samples tested. In contrast, only two of seven urine samples had detectable protease activity, and in these samples, activity was very low compared to that in serum.(ABSTRACT TRUNCATED AT 400 WORDS)

[Effect of CoQ10 on myocardial ischemia/reperfusion injury in the isolated rat heart]

It has been reported that CoQ10, ubiquionone, may have a protective effect on the mitochondrial injury induced by myocardial ischemia and reperfusion during open heart surgery. The purpose of this study was to investigate whether CoQ10 may enhance myocardial protection when given before ischemia, during ischemia or during reperfusion in the isolated working rat heart. Hearts (n = 6-9/group) from male Wistar rats were aerobically (37 degrees C) perfused (20 min) with bicarbonate buffer. In the first series of studies, this was followed by a 3 min infusion of St. Thomas' Hospital cardioplegic solution containing various concentrations of CoQ10. Hearts were then subjected to 39 min of normothermic (37 degrees C) global ischemia and 35 min of reperfusion (15 min Langendorff, 20 min working). The percent recovery of aortic flow (%AF) was 50.5 +/- 3.3% in the CoQ10 free controls versus 55.9 +/- 4.4, 62.1 +/- 3.1*% (*p < 0.05) in the 29, 44 and 58 mumol/L CoQ10 groups, respectively. Creatine kinase (CK) leakage during Langendorff reperfusion had a tendency to decrease in the 58 mumol/L group. In the second series of studies, 3 min of cardioplegia without CoQ10 and 38 min of ischemia (37 degrees C) were followed by a 15 min Langendorff reperfusion with 0 or 58 mumol/L of CoQ10 and 20 min working reperfusion. %AF was 53.2 +/- 2.7 and 39.2 +/- 7.1% in the 0 and 58 mumol/L CoQ10 groups, respectively. CK leakage had a tendency to increase in the 58 mumol/L group.(ABSTRACT TRUNCATED AT 250 WORDS)

Perioperative coronary artery spasm in modified Bentall's operation for annulo-aortic ectasia in Marfan's syndrome. A case report of perioperative chordal rupture of the mitral valve

We experienced a rare case of Marfan's syndrome with annulo-aortic ectasia, aortic regurgitation and Prinzmetal's variant angina. In a modified Bentall's operation (button technique), perioperative severe coronary artery spasm occurred in spite of the preventive use of nitroglycerin infusion, which resulted in profound ventricular fibrillation and subsequent chordal rupture of the mitral valve with Sellers IV regurgitation. Use of nicardipine contained in cardioplegia, continuous infusion of nicardipine and nitroglycerin after aortic declamping completely prevented coronary spasm throughout the course of a second surgery for mitral valve replacement. It is worthy to report this case because of rarities such as Marfan's syndrome accompanied by Prinzmetal's variant angina, perioperative coronary artery spasm in modified Bentall's operation, and perioperative chordal rupture of the mitral valve and progression of mitral valve regurgitation. We also stress the efficacy of a new calcium antagonist, nicardipine, to prevent coronary artery spasm during open heart surgery.

Characterization of a 50 kDa surface membrane protein on thymic stromal cells as an important factor for early T cell development

We previously reported that the nude mouse-derived splenic T cell clone, N-9F, exhibits a proliferative response to the SL10.3 thymic epithelial cell clone. In the present study we generated an Armenian hamster mAb, HS9, specific for SL10.3, which inhibited the N-9F's proliferative response to SL10.3. We performed thymocyte repopulation experiments using fetal liver cells and 2'-deoxyguanosine-treated thymic rudiments. After 14 days of culture, donor fetal liver cells proliferated and differentiated to CD4+CD8+ and CD4-CD8+ with some CD4+CD8- cells in the host thymic rudiments. However, most of the thymocytes remained at a CD4-CD8- immature stage in the presence of HS9 and the cell recovery was reduced to 30% of the control. Immunohistostaining and flow cytometry studies revealed that HS9 reacted with stromal cells of fetal thymus at the earliest from day 14 gestation. Neither thymocytes nor lymph node T cells were stained with HS9. HS9 antigen was distributed not only on thymic subcapsular and cortical stromal cells, but also on peripheral B cells in adult mice. The antigen that HS9 detected was found to be a 50 kDa surface membrane protein on thymic stromal cells. On the other hand, the 50 kDa molecule is associated with two other molecules of 80 and 100 kDa on the B cells. These data indicate that the HS9 antigen may have an important role for early T cell development, especially at a stage from CD4-CD8- to CD4+CD8+, and may have some unknown function on B cells.

[Results after cemented total knee arthroplasty: a follow-up study over 5-to-14 years]

Eighty-five cemented total knee arthroplasties were followed for five to fourteen years (mean 7.8 years). The clinical evaluation was excellent or good in 85% of this series. However, a complication developed in 15 knees (17.6%), and two thirds of these complications were found in the patello-femoral joint. One further case developed an infection (1.2%), and four others (4.7%) developed an aseptic loosening. Over all, 8 cases (9.4%) required revision surgery. Asymptomatic wear was seen to progress in some implants involving thin polyethylene, although their clinical results were rated as excellent. The outcome of the cemented knee arthroplasties was considered as acceptable at present, but improved surgical techniques and measures against polyethylene wear are required for future improvement in this surgery.

Biological responses in Caenorhabditis elegans to high magnetic fields

Here we describe a device for testing possible influences of high magnetic fields on biological processes, by which alternating-current magnetic stimuli as high as 1.7 T can be administered. Experiments with a simple multicellular organism, the nematode Caenorhabditis elegans, revealed that intermittent exposure to the magnetic fields modestly inhibited the animal's reproduction as well as its post-embryonic development, and caused a marked but transient derangement in its locomotory behavior. Available evidence indicates that alternating high magnetic fields can elicit both chronic and acute biological effects, but that the effects may be well tolerated or compensated for by the living organism.

[Clinical usefulness of MRI in acute phase of spinal multiple sclerosis--influence of high-dose steroid therapy in acute phase]

Magnetic resonance imaging (MRI) is useful for detecting spinal cord lesions in multiple sclerosis (MS). In this study, we have examined MRI for 14 patients (26 cases) with clinically definite MS and investigated the correlations between neurological and MRI findings before and after high-dose corticosteroid therapy (pulse therapy). High signal intensity areas on T2-weighted images (T2WI) were found in 25 of 26 cases. In 22 cases spinal level of clinically suspected lesions were involved in these high intensity areas. T1-weighted images (T1WI) after intravenous gadolinium with diethylenetriamine pentaacetic acid (Gd-DTPA) were also obtained and in 12 of 17 cases before pulse therapy, the symptoms and enhancement of lesions correlated well. The symptoms regressed in all cases after pulse therapy, and high-intensity areas in T2WI became less distinct. Gd-DTPA enhanced areas disappeared in 6 cases and became smaller in 3 of 12 cases. Additional pulse therapy in 3 cases effectively diminished the enhanced areas in these cases. In one patient who had repeated pulse therapy, MRI showed no enhancement. In two other patients who continued on decreased steroid dose had relapses, pulse therapy was therefore started again, providing a good recovery both clinically and radiologically. The changes of MRI findings and clinical course suggest that the pathological changes in spinal MS may be caused not only by demyelination but also by parenchymal edema. Clinical and MRI concordance was significantly better with Gd-DTPA enhanced T1WI than the high-intensity areas in T2WI. Contrast enhancement gives more information about disease activity and the reaction to therapy.

Dephosphorylation of abnormal sites of tau factor by protein phosphatases and its implication for Alzheimer's disease

The abnormally phosphorylated forms of tau factor are major constituents of neurofibrillary tangles in Alzheimer's disease brain. In order to investigate protein phosphatases which are related to dephosphorylation of abnormal phosphorylation sites, we examined the dephosphorylation of tau factor phosphorylated by three proline-directed type protein kinases. Tau factor phosphorylated by cdc2 kinase and tau protein kinase II was dephosphorylated by the holoenzyme of protein phosphatase 2A and calcineurin, while either the catalytic subunit of protein phosphatase 2A or protein phosphatase 2C could not catalyze the dephosphorylation. From the kinetic analysis, we concluded that tau factors phosphorylated by the protein kinases serve as good substrates for protein phosphatase 2A and calcineurin. On the other hand, tau factor phosphorylated by glycogen synthase kinase 3 alpha was dephosphorylated by the catalytic subunit of protein phosphatases 2A as well as the holoenzyme of protein phosphatase 2A and calcineurin. It has been reported that serines 199, 202 and 396 according to the numbering of the longest human tau isoform are among the major abnormal phosphorylation sites of tau factor. We synthesized two phosphopeptides which contained phosphoserines 199 and 202 or phosphoserine 396 and prepared the polyclonal antibodies specific for the phosphopeptides. Using these antibodies, we confirmed that the holoenzyme of protein phosphatase 2A and calcineurin could dephosphorylate phosphoserines 199, 202 and 396 in tau factor. The catalytic subunit of protein phosphatase 2A could dephosphorylate phosphoserine 396 but not phosphoserines 199 and 202. Neurofibrillary tangles in Alzheimer's disease brain were immunostained with both antibodies but the normal neurons in the normal aged brains were not. The results suggest that protein phosphatase 2A and calcineurin can be involved in the dephosphorylation of abnormal phosphorylation sites in tau factor and that the dephosphorylation of phosphoserine 396 is differently regulated from phosphoserines 199 and 202.

Immunohistochemical detection of advanced glycosylation end products within the vascular lesions and glomeruli in diabetic nephropathy

Numerous studies over the years have implicated advanced glycosylation end products (AGEs) in the pathogenesis of many of the complications of diabetes and normal aging. The recent development of specific antibodies against AGE-modified proteins has facilitated investigations on the formation and tissue distribution of AGEs. We used anti-AGE antibodies to localize AGEs within kidney specimens obtained from both diabetic and nondiabetic individuals. Immunohistochemical staining using anti-AGE antibody showed a high level of AGE accumulation in diabetic and aged vascular intima, particularly along the inner elastic layer of arteries. Positive staining also was observed within nodular and severe diffuse lesions of glomeruli as well as in hyaline deposits of arterioles. These data support a pathogenic role for advanced glycosylation in the renal complications of diabetes and aging.

[Enhanced delineation of the pancreatic duct in MR cholangiopancreatography (MRCP) with a combined use of secretin]

Magnetic resonance cholangiopancreatography (MRCP) is a method that can depict the main pancreatic duct non-invasively; however, its tendency to overestimate ductal stenosis is being noted. The authors used secretin to stimulate the output of pancreatic juice, which increased the signal of the main pancreatic duct and consequently minimized the occurrence of pseudostenosis artifacts in MRCP. MRCP images of 54 patients suspected of having pancreatic disease were visually evaluated by two observers before and after administration of secretin (1 clinical unit/kg). Improved delineation of the main pancreatic duct (68.5-59.3%, p < 0.05) and its side branches (40.7-29.6%, p < 0.05) was obtained with good interobserver agreement (kappa = 0.71-0.68).

Development of nested PCR based on the ViaB sequence to detect Salmonella typhi

For a rapid diagnosis of typhoid fever, we developed a nested PCR based on the nucleotide sequence encoding the Vi antigen. All Salmonella typhi strains along with a Salmonella paratyphi C strain were PCR positive. This assay was able to detect S. typhi at the single-cell level.

[A case report of a metaplastic carcinoma of the breast diagnosed by the preoperative needle biopsy]

A case of the metaplastic carcinoma, a rare type of the breast cancer, was reported. A 49-year-old woman noticed the left breast lump. Ultrasonography revealed a well circumscribed hypoechoic mass measuring 3 cm in diameter. The preoperative needle biopsy showed the invasive carcinoma with chondrometaplasia. The modified radical mastectomy along with the lymph node dissection was performed. There have been few reports of the metaplastic breast carcinoma diagnosed preoperatively.

Studies on the procedure for the construction of cellular protein databases employing micro two-dimensional electrophoresis: an HL-60 protein database

The procedure to construct a cellular protein database employing a micro two-dimensional electrophoresis (2-DE) technique was studied. Protein information on human cultured leukemic cell HL-60 was collected as an HL-60 protein database, which consists of a 2-DE polypeptide map of 670 recognized spots with spot numbering and information on isoelectric point (pI), molecular mass, and percent integrated density. The procedure employed in this report will be applicable for the comparative studies of cellular proteins and will help to construct comprehensive cellular protein databases.

[Relative hypoparathyroidism associated with CAPD treatment using normo-calcemic (3.5mEq/1) dialysate: an approach from transperitoneal calcium balance]

We investigated factors affecting net transperitoneal calcium balance (Ca-BL) and the level of parathyroid hormone in relation to stepwise changes in serum calcium, by short PET (peritoneal equibrium test during 240 min: using 2000 ml of 2.5% dextrose dialysate containing 1.75 mmol/L Ca) in uremic patients undergoing stable CAPD. We calculated Ca-BL (mg/effluent/PET) of 244 effluents obtained from 90 patients receiving calcium carbonate as a phosphate binder without vitamin D supplementation. Their serum calcium level corrected with albumin (cSCa), alkaline phosphatase activity (ALP) and intact-PTH level was 9.7 +/- 0.9 mg/dl, 236 +/- 83 mIU/ml and 153.0 +/- 172.4 pg/ml, respectively. We proposed two statistic significant regression lines between Ca-BL and total drainage effluent volume (Ca-BL = 133X - 0.056: r = 0.981, P < 0.001), cSCa (Ca-BL = -12.9X + 123.6: r = 0.941, P < 0.01). Total drainage volume (TDV) and cSCa were two major factors affecting Ca-BL. A TDV level of 2430 ml/240 min-PET or more was required for positive Ca-BL in cases with 9.5-10.0 mg/dl of cSCa, using this linear regression analysis. A cSCa level of 9.6 mg/dl or more was also required for positive Ca-BL in cases with 2400-2600 ml/240min-PET. We also proposed a significant linear regression line between the intact-PTH level and cSCa (i-PTH = -90.5X + 1015.8, r = 0.973, P < 0.01). This line suggest that 200 pg/ml of intact PTH was obtained by 9.0 mg/dl or less of cSCa level in 90 CAPD uremic patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Gait analysis of hemiplegic patients by measurement of ground reaction force

Ground reaction force during walking was measured and analyzed in 58 patients who had been hemiplegic for more than 6 months. Utilizing the impulse (area between a component curve and the baseline) as an assessment value, several parameters were selected to represent the characteristics of each component curve (vertical, fore-aft and lateral) of the ground reaction force, and correlated with the degree of motor recovery in the patients. As a result, a high correlation was found between these parameters and the degree of motor recovery, indicating that ground reaction force well reflects the degree of motor recovery, which is highly correlated with the gait ability of hemiplegic patients. This evaluation method would also be very helpful for objective and quantitative estimation of the gait of hemiplegic patients.

Enamel free areas in rodent molars--ultrastructure of basement membrane in rat tooth germ

At the cusp tip of rodent molar, there is a region of dentin without an enamel cap. This region is called enamel free area (EFA). The surface collagen arrangement has been reported to differ between the EFA and the dentin covered with the enamel (DCE). To clarify the cause of this difference, we observed the ultrastructure of the basement membrane and the distal ends of the inner enamel epithelium (IEE) in rats. At 20 days prenatal, distal ends of IEE were relatively flat on both the DCE and EFA. Ultrastructurally, there was no difference between the basement membranes. At newborn, no marked changes were observed in the morphology of the distal end of IEE on the DCE or the EFA, but aperiodic microfibrils perpendicular to basal lamina were denser and longer on the DCE than the EFA. At 2 days postnatal, cytoplasmic extensions from distal end of IEE penetrated through basal lamina, and these extensions were more developed on the DCE than the EFA. On the DCE, collagen fibrils ran into and between cytoplasmic extensions and were arranged perpendicular to the surface. On the EFA, collagen fibrils ran parallel to the surface, and few collagen fibrils ran into and between cytoplasmic extensions. These findings suggested that the differences in the collagen arrangement between the EFA and DCE are associated with the developmental state of aperiodic microfibrils in the basal lamina beneath IEE and the morphology of the distal end of IEE.

Changes in hepatic lobe volume in biliary tract cancer patients after right portal vein embolization

Changes in lobar volume of the liver and in total hepatic function were studied in 19 patients with biliary tract cancer who underwent right portal vein embolization as preoperative management for extensive liver resection. Computed tomography (CT) was performed to estimate liver volume before and approximately 11 days after embolization. An indocyanine green (ICG) test was performed before and 11 to 13 days after embolization. The calculated volume of the right lobe decreased from 761 +/- 181 cm3 to 625 +/- 110 cm3 11 days after embolization (P < .0001), whereas the volume of the left lobe increased from 420 +/- 94 cm3 to 555 +/- 110 cm3 (P < .0001). Thus, portal embolization produced a gain in left lobe volume of 136 +/- 62 cm3 and an almost equivalent loss in right lobe volume. The hypertrophy ratio of the left lobe, expressed as percentage of postembolization volume of the left lobe to preembolization size, of the 5 patients with diabetes mellitus (DM) was lower than that of the 14 patients without diabetes (116.7 +/- 6.3% vs. 140.4 +/- 18.4%; P < .005). The ICG disappearance rate in 16 patients improved from 0.163 +/- 0.034 to 0.177 +/- 0.027 (P < .05). The improvement was especially evident in 9 of 14 post-jaundice patients, although the rate decreased slightly in 2 patients without jaundice. We conclude that right portal vein embolization can produce a compensatory hypertrophy of the left lobe within 11 days without seriously affecting hepatic function. In diabetic patients, however, a longer interval between embolization and operation may be needed to achieve sufficient hypertrophy of the left lobe.

Intravascular ultrasound imaging of peripheral arteries as an adjunct to atherectomy: preliminary experience

12 atherosclerotic lesions in nine patients, including four restenoses after balloon angioplasty, were treated by atherectomy under the guidance of intravascular ultrasound (US). Echogenicities of the plaques and morphological alterations in the arterial walls produced by atherectomy were evaluated. The two-layered appearance of post-angioplasty restenoses was found to be inner fibrous intimal thickening with proliferation of smooth muscle cells and outer residual collagen-rich plaque. The deep cut surfaces were shown as concave U-shaped defects. Medial tissues were present in all cases where intravascular US demonstrated the disruption of a thin hyperechoic layer of the internal elastic lamina. Intravascular US imaging may provide valuable information on the degree, eccentricity and histological type of stenosis, the presence of calcification before atherectomy, and on the extent of excision and the morphological changes in the arterial wall after atherectomy.

Sarcoglycan complex is selectively lost in dystrophic hamster muscle

We recently reported that the dystrophin-associated glycoprotein (DAG) complex is biochemically divided into two subcomplexes: one is the dystroglycan complex comprised of 156DAG and 43DAG and the other is the sarcoglycan complex comprised of 50DAG, A3b, and 35DAG. A3b is a novel dystrophin-associated glycoprotein with an approximate molecular mass of 43 kd but is distinct from 43DAG. In the present study, we examined the striated muscles of the dystrophic hamster with anti-A3b antibody in addition to anti-50DAG, anti-43DAG, anti-35DAG, anti-dystrophin, and anti-laminin antibodies by both immunohistochemistry and immunoblot analysis and found that 50DAG, A3b, and 35DAG are selectively lost. This selective defect of the sarcoglycan complex in dystrophic hamster muscles may give rise to dystrophic changes in striated muscles. Thus, the differentiation of the dystrophin-associated glycoprotein complex into the dystroglycan and sarcoglycan complexes is important not only from a biochemical standpoint but also in understanding the cause of muscular dystrophy in the hamster. Our findings further show that the dystrophic hamster may serve as an animal model for a human disease, severe childhood autosomal recessive muscular dystrophy, which has recently been shown to result from a selective defect in the sarcoglycan complex.

The effects of tibial tunnel placement and roofplasty on reconstructed anterior cruciate ligament knees

Seventy-five anterior cruciate ligament (ACL) reconstructions augmented with the Kennedy Ligament Augmentation Device were evaluated according to classification of tibial drill-hole position on the basis of the anatomic landmarks of the ACL by two-dimensional radiographic imaging of the fully extended knee. The effects of roofplasty to avoid graft impingement were also assessed. The tibial drill-hole position was classified in relation to the medial intercondylar tubercle on anterior-posterior (AP) view, and in relation to Blumensaat's line (B-line) on lateral view. Arthroscopic evaluation of the ACL and incidence of chronic synovitis as well as Lysholm knee score, manual knee tests, knee extension and flexion angles, and knee tester measurements were performed. The results indicated that the knee joints in which the tibial drill hole was positioned laterally from the medial intercondylar tubercle or in which the tibial drill hole was positioned anteriorly to the B-line showed a tendency to develop more postoperative chronic synovitis. The knees in which the tibial drill hole was positioned anteriorly to the B-line also showed larger AP laxity. There was no difference between the non-roofplasty and roofplasty groups.

Intraosseous ganglion

A 48-year-old man presented with pain in the right wrist. A roentgenogram showed symmetrically located, well-demarcated lucencies in both scaphoids. These lesions showed homogeneous intermediate signal intensity on T1-weighted MR images and homogeneous high signal intensity on T2*-weighted MR images. Histopathological analysis revealed the lesion in the right hand as an intraosseous ganglion. The reason why the lesions were located on the palmar side is discussed.